During normal communication system transmission, a person's voice is digitized, compressed, and divided into small packets of encoded binary data. The packets are sent over an unregulated network which results in them arriving at far-end receivers with varying amounts of delay on each packet. The far-end receivers put the packets back in the correct order then uncompresses (or, synonymously, decodes) the encoded binary data and thus provides a continuous audio signal to a listener, which sounds like a slightly delayed copy of the original voice.
In order to compensate for variable network delays jitter buffers are usually employed by the receivers. Slight jitter in arrival time is thus eliminated, as the contents of the buffer are clocked out by a synchronous local clock at the receiver. A large static jitter buffer can be designed into the receiver to optimize performance against large amounts of network delay jitter at the cost of large delays which will be noticed by users; on the other hand, a small jitter buffer can be used which will introduce minimal delays but at the cost of significant packet loss. In this case, call quality degrades when the network jitter exceeds the size of the jitter buffer.
Thus, there exists a tradeoff between long delays/low packet loss and short delays/higher packet loss. Therefore a need exists for a method and apparatus for jitter buffering within a communication system that optimizes a jitter buffer for better system performance.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions and/or relative positioning of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of various embodiments of the present invention. Also, common but well-understood elements that are useful or necessary in a commercially feasible embodiment are often not depicted in order to facilitate a less obstructed view of these various embodiments of the present invention. It will further be appreciated that certain actions and/or steps may be described or depicted in a particular order of occurrence while those skilled in the art will understand that such specificity with respect to sequence is not actually required.